According to NASA, the boldest test flight ever is not the Wright Brothers at Kitty Hawk, Chuck Yeager’s breaking of the sound barrier, or even Yuri Gagarin becoming the first human in space. They argue it is actually the first flight of the Space Shuttle, which is marking its 40th anniversary in April 2021.
STS-1 (STS being short for ‘Space Transportation System’) brought to an end a six-year period in which no American had travelled into space, the longest since the beginning of the Space Race.
Construction on the first Shuttle began in California in 1975. Built by North American Rockwell, it was named ‘Columbia’ after the ship that became the first American vessel to circumnavigate the world in the late 1700s.
It was originally planned to launch in 1979, but problems with its engines and thermal protection system caused a delay until 1981.
Even though the Shuttle would later carry as many as seven astronauts, for STS-1 there were just two: a commander and pilot. NASA selected its most experienced astronaut, John Young, as commander. Young had flown in space four times before and had walked on the Moon as commander of Apollo 16. At 50, he would become the oldest person to fly in space to that point and also the first to need to wear reading glasses. He was paired with rookie Bob Crippen. Crippen, like Young, was a former test pilot for the Navy.
Every US spacecraft prior to Columbia had had several uncrewed test launches before NASA ever contemplated putting astronauts inside. For STS-1, however, the first time that Columbia ever launched was with Young and Crippen inside.
They did have ejection seats, but Crippen labelled them as “primarily a placebo” as “there was a ton of flame from the solid rocket boosters. If you ejected, you would have to go through that and you would get very toasty”.
Columbia left the launchpad at 12:00:03 UTC on 12 April 1981, which was coincidentally the 20th anniversary of Yuri Gagarin becoming the first human in space.
As part of their checks once they were in orbit, Young and Crippen had to open the Shuttle’s payload bay doors. This was a necessity to allow the doors’ radiators to release excess heat and prevent the cooling system from being overwhelmed.
Doing so, however, revealed that there were tiles missing from around Columbia’s Orbital Manoeuvring System (OMS) pods, seemingly shaken loose during launch. These tiles were part of the Shuttle’s heat shield, needed for it to make a safe re-entry through the atmosphere at the end of the mission.
While the tiles around the OMS pods were not essential to the Shuttle’s safety, it made NASA wonder if any of the more crucial tiles on its belly were also missing.
In a ploy that would remain classified for decades, NASA turned to one of the National Reconnaissance Office’s (NRO) secret KH-11 Keyhole spy satellites for help. It was the only thing able to take pictures that of a good-enough resolution to be of use. Even the very existence of the NRO was classified in 1981, and so only 15 people in all of Mission Control were privy to the plan.
The KH-11 had only three chances lasting less than a minute each to take the necessary pictures, but it managed to get the job done. NASA was able to confirm that the tiles on Columbia’s underside were intact and would pose no danger during the re-entry process, which began a few hours short of three days after launch.
Re-entry was the last major ‘unknown’ of STS-1. NASA’s predictions on Columbia being able to make it were based solely on scaled-up calculations from wind-tunnel tests using a model of the Shuttle no bigger than a toy.
Columbia re-entered the atmosphere at over 17,000 miles an hour, coming down in a series of s-shaped bends to bleed off speed. This wasn’t like Apollo, which returned to Earth hanging from a parachute.
Onboard computers took the Shuttle through most of this process, but once it had slowed to under Mach 5 (3,800 miles an hour) Young took over control. He lined Columbia up with the huge 12.5-mile-long Rogers Dry Lake at Edwards Air Force Base in California.
During launch the Shuttle was attached to an external fuel tank (painted white for STS-1 along with STS-2 before being left its ‘natural’ rusty orange for all future flights to save somewhere in the region of 270kg) that provided fuel for its three main engines. This tank was jettisoned once the Shuttle reached orbit, rendering the main engines inert for the rest of the mission.
It meant that during its return to Earth the Shuttle was an unpowered glider. With no engines, there were no second chances at landing if the first attempt went awry.
The angle of approach was extremely steep at 20 degrees and Columbia was still travelling at 360 miles an hour just two miles away from the runway, but in the final moments before touchdown Young started to level out and pulled the nose up slightly to slow down to 215 miles an hour.
Guided down by a chase plane piloted by a fellow astronaut, and with an estimated 250,000 people watching in person, Young and Crippen made a smooth touchdown on the lakebed. During the landing process Young’s heartbeat peaked at 135 beats per minute – by comparison, when he landed on the Moon it hadn’t exceeded 90.
That alone gives credence to NASA’s claim that STS-1 was the ‘boldest test flight in history’. It ushered in the ‘Shuttle era’, during which Columbia and its four siblings (Challenger, Discovery, Atlantis and Endeavour) made a total of 135 flights until its end in 2011.
Unfortunately, Columbia’s story didn’t end happily. In a twist of irony, some of the thermal protection tiles on its left wing were damaged by debris during launch at the start of its 28th mission (STS-107) in 2003. This damage meant it couldn’t cope with the heat of re-entry 15 days later – it disintegrated over Texas with the loss of the seven astronauts onboard.